TUCSON, Ariz. — The McKale Center crowd buzzed in the minutes before the opening tip, more like a postseason game than another conference game.

With support like that, it's not hard for top-ranked Arizona to get off to a fast start.

Charged by the mojo created inside one of college basketball's best home-court advantages, the Wildcats raced out to a big lead and held on down the stretch to remain unbeaten with a 69-57 win over Colorado on Thursday night.

"This is why we love McKale; we feel like it's like this all the time," said Arizona forward Brandon Ashley, who had 15 points.

Arizona (19-0, 6-0 Pac-12) had a week off after blowing out rival Arizona State and was still in a groove early, building a 14-point lead in the opening six minutes.

The big lead allowed the Wildcats some leeway in the second half when things didn't go quite as well.

Arizona struggled from the perimeter, making 3 of 15 from 3-point range, had a rare night when it didn't outrebound the opposition (32-32) and missed three free throws in the closing 72 seconds to keep the game from becoming a rout.

The Wildcats pulled it out thanks to the big start and 44 points in the paint, allowing them to tie — with the 1992-93 and 1997-98 teams — for the longest winning streak in school history.

Nick Johnson led Arizona with 18 points and Aaron Gordon added 12.

"Our second half maybe wasn't as good as our first, but there are always good lessons to be learned from that and still leave with the win," Arizona coach Sean Miller said.

A year after nearly pulling off an upset in the desert, Colorado (15-5, 4-3) had no chance for late-game heroics in its third game without leading scorer Spencer Dinwiddie.

The Buffaloes struggled to slow Arizona's bevy of scorers and couldn't shoot their way out of the big early hole, falling to 0-16 all-time against No. 1 teams.

The Bruins (15-4, 4-2 Pac-12) have won nine of their last 11 against Stanford, including a sweep last season. Jordan Adams added 19 points, Kyle Anderson had 13 points, seven rebounds and 10 assists, and Norman Powell had 13 points.

Arizona St. 79, Utah 75

At Tempe, Ariz., Jahii Carson scored 23 points, eight in a decisive five-minute span late in the game, as Arizona State held on to beat Utah.

Jonathan Gilling added 13 points, including 3 of 3 3-pointers, a critical one coming with 1:40 to play for the Sun Devils (14-5, 3-3 Pac-12).